Conventionally, a known fuel vapor leakage detection device may be configured to detect leakage of fuel vapor, which is from a fuel tank and/or from a canister, which is to adsorb fuel vapor caused in a fuel tank. The fuel vapor leakage detection device includes, for example, a pump, a switching valve, and an air filter. The pump is to pressurize an interior of both a fuel tank and a canister or to reduce pressure in the fuel tank and the canister. The switching valve is to switch between communication of both the fuel tank and the canister with the pump and communication of both the fuel tank and the canister with the atmosphere. The air filter is to remove foreign matter contained in air drawn with the pump from the atmosphere. The fuel vapor leakage detection device includes two housings, each of which is in a bottomed tubular shape and is formed of resin. The two housings accommodate the pump, the switching valve, and the air filter. The fuel vapor leakage detection device is manufactured by, for example, implementing laser welding disclosed in, for example, Patent Document 1 on two resin members to connect the two resin members to form a housing and to maintain an airtight property of an interior of the housing to the outside.
(Patent Document 1)
Publication of unexamined Japanese patent application No. 2009-262576
The laser welding described in Patent Document 1 is implemented on the resin members, and one of the resin members has a stopper surface, which is in addition to a portion to be welded by laser. The stopper surface is to define a distance between the one resin member and the other resin member. When the two resin members are joined together with the laser welding, the one of the resin members is in contact with the other of the resin members at the portion, which is welded by laser, and at the stopper surface. The pump, the switching valve, and the like may be connected with the one resin member. Therefore, in the configuration of the housing manufactured by using the laser welding according to Patent Document 1, oscillation of the pump and/or the like may be propagated via the stopper surface to the other resin member easily. Consequently, the configuration may cause large noise.